Proceedings of the XLV Italian Society of Agricultural Genetics - SIGA Annual Congress

Salsomaggiore Terme, Italy - 26/29 September, 2001

ISBN 88-900622-1-5

Poster Abstract

THE GERANIL GERANIL HYDROGENASE GENE FROM PEACH (PRUNUS PERSICA [L.] BATSCH) IS TRIGGERED BY STRESS FACTORS

GIANNINO D.*, CONDELLO E.*, FRUGIS G.*, NICOLODI C.*, BRUNO L.**, COZZA R.**, BITONTI M.B.**, INNOCENTI A.M.**, MARIOTTI D.*

* Istituto di Biochimica ed Ecofisiologia Vegetali del Consiglio Nazionale delle Ricerche. Via Salaria km 29,300. 00016. Monterotondo Scalo, Roma

Tel 06 90672539 Fax 06 9064492

mari@mlib.cnr.it

** Dipartimento di Ecologia dell’Università della Calabria. Ponte Bucci. 87030. Arcavacata di Rende, Cosenza

Tel 0984 492965, Fax 0984 492964

b.bitonti@unical.it

peach, geranil geranil hydrogenase, chlorophyll synthesis, insect damage

The geranil geranil reductase (GGH) plays a key role in the chlorophyll synthesis by reducing the geranil chlorophyll a complex to the phytil chlorophyll a. The enzyme also reduces free geranil geranil biphosphate to phytil biphosphate. The addition of the phytol chain to the tetrapyrrolic ring allows the integration of chlorophyll into the plastid membranes. The peach GGH gene was characterised as a result of DDRT-PCR experiments aimed at cloning differentially expressed genes from leaves borne on juvenile and adult shoots. The gene was found to be highly conserved among the members of drupoideae sub-family (almond, cherry and plum). Though the copy number varied according to species (single copy in peach and cherry, two in almond and plum), the single intron position was conserved among drupoideae and less related species such as soybean. Gene expression analysis indicated that GGH messages were signalled in chlorophyll containing tissues and not detected in root and woody stems. Tissues from apical tips, developing leaves and fruits exhibited the highest gene expression, whereas fully expanded leaves and sepals had a low abundant message. In situ analysis showed that messages were located in the blastoderms and protruding leaves, but not in the apical dome. In fully expanded leaves the messages were located in the parenchima and palisade cells, but not in the vases. Interestingly, strong expression was detected in cells affected by insect puncture and in the cells surrounding the lesion corresponding to the chlorotic area.